Stop watch mechanism



1944. J. H. FURBACH STOP WATCH MECHANISM Filed July 16, 1942 3 Sheets-Sheet l [lu u/l0)- Ja/m fie/75 u/"Mm ".1' W am Aug. 8, 1944.

J. H. FURBACH STOP WATCH MECHANISM Filed July 16, 1942 3 Sheets-Sheet 2 3 h 2 Kl b J 9 L 3 J 7 3 J 3 5 2 2 3. A 1 4 a 7 I v o 2 9 0 2 x 2 Z 6 O John Ham Furbac/r and Aug. 8, 1944. J. H. FURBACH STOP WATCH MECHANISM Filed July 16, 1942 3 Sheets-Sheet 5 Iuucnfar (Jo/m [fa/7s Fmbar/i J7 By QM and Wm; m

Patented Aug. 8, 1944 UNITED STATES PATENT OFFICE STOP WATCH-MECHANISM John Hans Furbach, Amarillo, Tex. 7

Application July 16, 1942, Serial No. 451,176

IOlaim. cits-rs) The invention relates to improvements in stop watches, and more particularly to an improved sweep second hand operating and fiyback mechanism, the primary object of the invention being to provide a simplified and more efiicient mechanism of this character having fewer component parts.

Other important objects and advantages of the invention will be apparent from a reading of the following description taken in connection with the appended drawings, wherein for purposes of illustration a preferred embodiment of the inventionis shown.

In the drawings:

Figure 1 is a schematic elevational view showing the mechanism in initialnormal position.

Figure 2 is a view similar to Figure 1 showing the parts operated to the intermediate position.

Figure 3 is a view similar to Figure 2 but showing the parts operated into the final position bei Figure 6 is a transverse vertical sectional view taken through the crown.

Figure 7 is an enlarged fragmentary top plan and horizontal sectional view showing details of the toothed and notched wheel. I

Referring in detail to the drawings, the numeral 5 generally designates a stop watch case and works involving a sweep second hand (not shown) which is operated by the center wheel 6 on which is a heart wheel 1. A jeweled bridge 8 supports the heart wheel and the center wheel 6 substantially at the center of the works. Spaced to the left of the center Wheel 6 is the fourth wheel 9 which is adapted to be operatively connected to the center wheel by the intermediate wheel lll which is mounted on the upper portion of one arm of a U-shaped lever spring H which is mounted to the watch mechanism as indicated by the numeral l2 to the left of the fourth wheel 9. The arm of the lever spring H on which the intermediate wheel ii! is mounted is positioned between the fourth Wheel and the center wheel, this portion of the lever spring ll terminating in a pawl l3 carried by a bridge l4 connected to the lever spring H. The effective terminal of the pawl 13 is upwardly directed to engage in the notches between adjacent ones of the 24 ratchet teeth l5 which are provided on the periphery of the wheel l5 which is rotatably mounted by a countersunk screw ll substantially directly above the intermediate wheel l3.

spring pawl 18 is mounted along the edge wall of the works, with its laterally inwardly directed terminal constantly engages the ratchet teeth l5 to prevent reverse rotation of the wheel [6.

The wheel I6 comprises the forwardly projecting cylindrical part I9 which projects forwardly through an opening .20 in the plate'of the works. The cylindrical portion is formed with'eight similar radial slots which are equally circumferentially spaced, the slots being designated 2| and the segmental abutments defined therebetween by numeral 22. a i I A crown 23 is mounted alongside the wheel iii in a'suitable opening in the watch casing and works, the crown havingfreely movable therein the stem 24 which has lateral pins 25 working in opposite sides of a vertical slot 26 which limits the movement of the crown relative to the stem 24. The stem and crown are arranged to wind the watch and also set it, and also to start, stop, and flyback the sweep second hand.

Th lower end of the crown overrides a click 21 which is horizontally pivoted as indicated by the numeral 28 on the free end of the lever spring 29 which is suitably anchored along the right hand upper portion of the watch as indicated by the numeral'30, the said free end having a notch and shoulder 3| which cooperates with the click, the latter having an overhanging portion 32 which is adapted to rest upon the upper side of the lever spring 29 as shown in Figure l of the drawings. 'The lower end of the crown 23 is adapted to engage the curved upper surface of the click when the crown is depressed, and to depress and down tilt the click into engagement with the adjacent one of the ratchet teeth IS on the wheel l6, against the resistance of the lever spring 29. The lever spring 29 is mounted behind the plate as indicated in Figure '7 of the drawings.

In front of the plate 33 and pivoted at the point 34 to the plate is the fiyback lever which is generally designated 35 and which has close to its pivot the upturned nose 36 which has a straight upper surface and a rounded under surface for cooperation with the peripheral surfaces of the segments 22 on the wheel l6. To the right of the ivot 34 the flyback lever 35 comprises an irregular plate terminating in a depending inwardly curved arm which terminates at its lower end in a laterally inwardly directed toe adapted to cooperate with the periphery of the heart wheel 1 in a well known manner. A bowed flyback operating spring 39 is mounted on the pivot 34 and has its opposite end anchored as indicated by the numeral 40 adjacent the right hand extremity of the fiyback lever. The crown 23 is normally held in its elevated position by the tension of the upper lever spring 29, while the return spring 39 on the flyback lever 35 normally holds the fiyback lever 35 engaged with the wheel 1, whereby the heart wheel is kept from rotating the sweep second hand around the face of the watch (not shown).

As soon as the crown 23 is depressed, assuming that the watch works is running, the lever spring 29 is depressed so that the click engages one of the teeth l5 of the wheel I 6 and in so doing rotates the wheel and causes the flyback lever 35 to be moved by the wheel I6 and retracted from the heart wheel, so that the heart wheel is then free to run and move with the sweep second hand, this action being accompanied by connection of the fourth wheel 9 with the center wheel 6 by the displacement of the intermediate wheel I0. When the crown is released and then depressed a second time the sweep second hand will be stopped. Then, by releasing and depressing the crown a third time the fiyback lever 35 is permitted to resume engagement with the heart wheel 1 in a manner to turn the heart wheel and hence the sweep second back to zero.

In the first position of the parts illustrated in Figure l of the drawings, the click 2! is out of engagement with the teeth l5 of the wheel l5 while the nose 36 of the flyback lever 35 is engaged in one of the slots 2|, the pawl l3 engaging the periphery of a segment 22.

In the second position shown in Figure 2. of the drawings, the crown having been depressed the second time and released, the click 2! is out of engagement with the wheel l6, while the nose 36 of the fiyback lever has come out of the slot in the wheel l6 and has assumed the first of two positions against the periphery of the adjacent segment of the wheel IS, the nose of the pawl l3 having become disengaged from the eripheral surface of the corresponding segment and having fallen into the adjacent notch.

In the third position of the parts shown in Figure 3 of the drawings, the crown having been depressed the third time and then released, the click 2'! is disengaged from the wheel 5, the terminal of the pawl l3 has come out of the slot in the wheel l6 and has assumed the first of the two positions on the periphery of the next segment of the wheel l5, and the nose 36 of the fiyback lever has assumed the second of two positions on the periphery of the segment of the wheel l6. It is obvious that the next depression of the crown displaces the described parts into the position shown in Figure 1 of the drawings, by reason of which the sweep second hand is returned to zero position.

Although there is shown and described herein a preferred embodiment of the invention, it is to be definitely understood that it is not desired to limit the application of the invention thereto, except as may be required by the scope of the subjoined claim.

Having described the claimed as new is:

In a stop watch mechanism for operating a sweep second hand, said mechanism comprising a center wheel adapted to operate the sweep second hand, a heart wheel on said center wheel, a spring pressed flyback lever pivotally supported to normally engage said heart wheel and return the sweep second hand to zero position, said fiyback lever having a nose at one side of its pivot, a slotted wheel having ratchet teeth on its periphery and having an axial extension formed with radial slots defining segments between them, with which segments and slots the nose on the flyback lever is arranged to operatively engage, a spring dog engaging the teeth of said slotted wheel to prevent reverse rotation thereof, said mechanism having a fourth wheel at one side of said center wheel, a first lever spring carrying an intermediate wheel normally connected with said fourth wheel, said first lever spring including a pawl engaging with either the slots or the segments of the slotted wheel in accordance with the position of the slotted wheel, a second lever spring anchored at one side of said mechanism and having its free end located adjacent to said slotted wheel, a click pivoted on the free end of said second lever spring, a de pressible crown over said click, said crown having a relatively slidable stem connected thereto for winding and setting said mechanism, said crown being adapted to be depressed to engage said click with one of the ratchet teeth of said slotted wheel to turn the same to cause the nose of the fiyback lever to be displaced and said pawl to be displaced, thereby removing the fiyback lever from engagement with the heart wheel, and freeing the heart wheel for rotation while operatively connecting said fourth and center wheels for moving the sweep second hand away from zero position.

invention, what is JOHN HANS FURBACH. 

